Influence of pre-precipitation on the multi-stage hot deformation behavior of an Al-Cu-Mg-Zr alloy: Experiments and integrated modeling

• Published in: Materials & design Vol. 232; p. 112119
• Main Authors: Bo, Guowei, Qin, Renbao, Li, Wei, Tang, Jie, Jiang, Fulin, Xiao, Gang, Teng, Jie, Fu, Dingfa, Zhang, Hui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023; Elsevier
• Subjects: Al alloy; Flow stress; Hot deformation; Microstructure; Hot deformation; Model; Al alloy; Microstructure; Flow stress
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2023.112119

[Display omitted] •A microstructure-based constitutive model was developed to predict whole flow stress evolution during single-stage hot deformation.•A novel approach capable of modeling the whole flow stress evolution during multi-stage hot deformation was proposed.•The work hardening and dynamic recovery coefficient were mainly dependent on solute solubility and deformation conditions, respectively.•The work hardening and recovery coefficients of the second-pass deformation were linearly dependent on the logarithm of interval holding time. Most industrial hot working operations of heat treatable Al alloys are frequently comprised of several successive deformation stages, and therefore the in-depth understanding and better prediction of flow stress evolution during multi-stage thermomechanical processing are required in modern aluminum industries. In this work, the effects of pre-precipitation microstructures on the complicated flow stress behaviors of an Al-Cu-Mg-Zr alloy during multi-stage hot deformation were first investigated. Further, a new integrated model was developed to predict the multi-stage flow stress behaviors. Concretely, by considering dynamic microstructural evolution, a microstructure-based constitutive KM + Avrami model in which the parameters could be well described by the empirical relationship with the Zener-Hollomon parameter was developed to predict the whole flow stress evolutions of single-stage deformation. Then, a novel approach was proposed to describe the whole flow behaviors during multi-stage hot deformation by integrating the microstructure-based constitutive approaches and a physically-based recovery model for static softening. A good modeling capability and agreement between the modeled and experimental flow stress results was found for the studied alloy with three types of pre-precipitation microstructures. In addition, the in-depth dynamic and static softening mechanisms with the influences of pre-precipitation were also discussed based on modeling analysis and microstructural observations.